Run tests Docker in Docker (#261)

* Try running tests in Docker

* Spawn new container for each test

* Store test artifacts outside of mount

* When requested, build up to date image in test script

* sudo is unneccessary in containerized test env

* Skip azure test

* Backdate fixture file in JSON database

* Pin versions for azure tools

* Mount temp volume for /var/lib/docker to prevent dangling ones created by VOLUME instruction

* Fail backdating tests with message

* Add some documentation on test setup

* Cache images

* Run compose stacks with shortened default timeout

test/dropbox/run.sh

@@ -6,9 +6,10 @@ cd "$(dirname "$0")"
 . ../util.sh
 current_test=$(basename $(pwd))
 
-cp user_v2.yaml user_v2_ready.yaml
-sudo sed -i 's/SERVER_MODIFIED_1/'"$(date "+%Y-%m-%dT%H:%M:%SZ")/g" user_v2_ready.yaml
-sudo sed -i 's/SERVER_MODIFIED_2/'"$(date "+%Y-%m-%dT%H:%M:%SZ" -d "14 days ago")/g" user_v2_ready.yaml
+export SPEC_FILE=$(mktemp -d)/user_v2.yaml
+cp user_v2.yaml $SPEC_FILE
+sed -i 's/SERVER_MODIFIED_1/'"$(date "+%Y-%m-%dT%H:%M:%SZ")/g" $SPEC_FILE
+sed -i 's/SERVER_MODIFIED_2/'"$(date "+%Y-%m-%dT%H:%M:%SZ" -d "14 days ago")/g" $SPEC_FILE
 
 docker compose up -d --quiet-pull
 sleep 5
@@ -42,7 +43,6 @@ fi
 
 # The third part of this test checks if old backups get deleted when the retention
 # is set to 7 days (which it should)
-
 BACKUP_RETENTION_DAYS="7" docker compose up -d
 sleep 5
 
@@ -59,7 +59,3 @@ elif echo "$logs" | grep -q "None of 1 existing backups were pruned"; then
 else
   fail "Pruning failed, unknown result: $logs"
 fi
-
-
-docker compose down --volumes
-rm user_v2_ready.yaml